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Possible Methods (possible + methods)
Selected AbstractsLarge-scale ecology and hydrology: an introductory perspective from the editors of the Journal of Applied EcologyJOURNAL OF APPLIED ECOLOGY, Issue 2000S.J. Ormerod 1. Five key features characterize large-scale factors in ecology: (a) they incorporate some of the most major of all ecological phenomena , the ranges of organisms, patterns of diversity, variations in ecosystem character and environmental processes such as climate, biogeochemical cycles, dispersal and migration; (b) they involve interactions across scales through both top-down and bottom-up processes; (c) they are multifaceted, and hence require an interdisciplinary perspective; (d) they reflect the cumulative effects of anthropogenic change across all scales, and so have direct relevance to environmental management; (e) they invariably exceed the range of classical ecological experiments, and so require alternative approaches to hypothesis testing. 2. Against this background, a recent research initiative on large-scale ecology and hydrology was funded jointly by the Natural Environment Research Council (NERC) and the Scottish Executive Rural Affairs Department (SERAD). Outputs from this programme are reported in this special issue of the Journal of Applied Ecology, and they illustrate some of the ecological research that is currently in progress in the UK at large spatio-temporal scales. 3. The spatial scales investigated in the papers range from hectares to whole continents, and much of the work reported here involves modelling. Although the model outputs are intrinsically valuable, several authors express the need for improved validation and testing. We suggest that this is an area requiring much development, and will need considerable innovation due to the difficulties at the scales involved (see 1d). Possible methods include: model applications to new circumstances; large-scale environmental manipulations; large-scale surveys that mimic experimental protocols; support from process studies at smaller scales. These alternatives are not mutually exclusive, and all can allow robust hypothesis testing. 4. Much of the work reported here is interdisciplinary linking, for example, geographical, mathematical, hydrological, hydrochemical and ecological concepts (see 1c). We suggest that even stronger links between environmental disciplines will further aid large-scale ecological research. 5. Most important in the context of the Journal of Applied Ecology, the work reported in this issue reveals that large-scale ecology already has applied value. Sectors benefiting include the conservation of biodiversity, the control of invasive species, and the management of land and water resources. 6. Large-scale issues continue to affect many applied ecologists, with roughly 30,40% of papers published in the Journal of Applied Ecology typically confronting such problems. This special issue adds to the growing body of seminal contributions that will add impetus to further large-scale work. Moreover, occurring in a period when other areas of biology are increasingly reductionist, this collection illustrates that, at least with respect to large-scale environmental problems, ecology still holds centre ground. [source] Processing methods for partially encrypted data in multihop Web servicesELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 5 2008Kojiro Nakayama Abstract Message layer security is necessary to ensure the end-to-end security of Web services. To provide confidentiality against the intermediaries along the message path, XML encryption is used to partially encrypt the message. Because the data structure is changed by the partial encryption, the encrypted message is no longer valid with respect to the original schema definition. Thus, problems occur regarding the processing of the schema validation and the data binding by the intermediary. In this paper, we discuss two possible methods to solve these problems. The first method is to transform the original schema definition. The second is to transform the received message. We examined these methods by applying them to demonstration experiment of Web services. © 2008 Wiley Periodicals, Inc. Electron Comm Jpn, 91(5): 26, 32, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10112 [source] Methods for determining labile cadmium and zinc in soilEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2000S. D. Young Summary Isotopically exchangeable cadmium and zinc (,E values') were measured on soils historically contaminated by sewage sludge and ones on zinc-rich mine spoil. The E -value assay involves determining the distribution of an added metal isotope, e.g. 109Cd, between the solid and solution phases of a soil suspension. The E values for both metals were found to be robust to changes in the position of the metal solid,solution equilibrium, even though the concentration of dissolved metal varied substantially with electrolyte composition and soil:solution ratio. Concentration of labile metal was also invariant over isotope equilibration times of 2,6 days. The use of a submicron filtration procedure, in addition to centrifuging at 2200 g, proved unnecessary if 0.1 m Ca electrolyte was used to suspend the soils. The proportion of ,fixed' metal, in non-labile forms, apparently increased with increasing pH, although there was considerable variation in both sets of contaminated soil. Zinc and cadmium in the sludged soils were similarly labile. Several possible methods for the measurement of chemically reactive metal were explored for comparison with E values, including single extraction with 1 m CaCl2 and a ,pool depletion' (PD) method. The latter involves comparing solid,solution metal equilibria in two electrolytes with differing degrees of (solution) complex formation, 0.1 m Ca(NO3)2 and CaCl2. Both the single extraction and the PD method gave good estimates of E value for Cd, although the single extraction was more consistent. Neither technique was a useful substitute for determining labile Zn, because of weak chloro-complexation of Zn2+. We therefore suggest that 1 m CaCl2 extraction of Cd alone be used as an alternative to E values to avoid the inconvenience of isotopic dilution procedures. [source] ZnO Nanostructures for Dye-Sensitized Solar CellsADVANCED MATERIALS, Issue 41 2009Qifeng Zhang Abstract This Review focuses on recent developments in the use of ZnO nanostructures for dye-sensitized solar cell (DSC) applications. It is shown that carefully designed and fabricated nanostructured ZnO films are advantageous for use as a DSC photoelectrode as they offer larger surface areas than bulk film material, direct electron pathways, or effective light-scattering centers, and, when combined with TiO2, produce a core,shell structure that reduces the combination rate. The limitations of ZnO-based DSCs are also discussed and several possible methods are proposed so as to expand the knowledge of ZnO to TiO2, motivating further improvement in the power-conversion efficiency of DSCs. [source] Laser Doppler flowmetry in endodontics: a reviewINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2009H. Jafarzadeh Abstract Vascular supply is the most accurate marker of pulp vitality. Tests for assessing vascular supply that rely on the passage of light through a tooth have been considered as possible methods for detecting pulp vitality. Laser Doppler flowmetry (LDF), which is a noninvasive, objective, painless, semi-quantitative method, has been shown to be reliable for measuring pulpal blood flow. The relevant literature on LDF in the context of endodontics up to March 2008 was reviewed using PubMed and MEDLINE database searches. This search identified papers published between June 1983 and March 2008. Laser light is transmitted to the pulp by means of a fibre optic probe. Scattered light from moving red blood cells will be frequency-shifted whilst that from the static tissue remains unshifted. The reflected light, composed of Doppler-shifted and unshifted light, is returned by afferent fibres and a signal is produced. This technique has been successfully employed for estimating pulpal vitality in adults and children, differential diagnosis of apical radiolucencies (on the basis of pulp vitality), examining the reactions to pharmacological agents or electrical and thermal stimulation, and monitoring of pulpal responses to orthodontic procedures and traumatic injuries. Assessments may be highly susceptible to environmental and technique-related factors. Nonpulpal signals, principally from periodontal blood flow, may contaminate the signal. Because this test produces no noxious stimuli, apprehensive or distressed patients accept it more readily than current methods of pulp vitality assessment. A review of the literature and a discussion of the application of this system in endodontics are presented. [source] Application of Surface Photo Charge Effect for Milk Quality ControlJOURNAL OF FOOD SCIENCE, Issue 7 2009O. Ivanov ABSTRACT:, The potential difference induced by the interaction of samples with electromagnetic radiation in the visible region is used for food characterization. In this article we show that the above effect can be applied for the understanding of specific reactions and processes taking place in milk such as change of the acidity and changes caused by an added reagent. We also propose a technique for instantaneous detection of inhibitors of starter bacteria in milk. We suggest possible methods for quality control of milk and other foods. Instantaneous results, practically no expenses for consumables, and possibilities for field measurements will be some of the advantages of this approach. [source] Iatrogenic complications and risks of nerve conduction studies and needle electromyographyMUSCLE AND NERVE, Issue 5 2003Amer Al-Shekhlee MD Abstract Electrodiagnostic procedures are routinely performed in patients with a variety of neuromuscular disorders. These studies are generally well tolerated and rarely thought to be associated with any significant side effects. However, needle electromyography is an invasive procedure and under certain situations has the potential to be associated with iatrogenic complications, including bleeding, infection, nerve injury, pneumothorax, and other local trauma. Similar complications are possible if needles are used for either stimulating or recording. In addition, like all other electrical devices and monitoring equipment connected to patients, electrodiagnostic testing carries the risk of stray leakage currents that under certain circumstances can result in electrical injury, especially in patients in the intensive care setting. Similarly, certain precautions are required during nerve conduction studies (NCS) in patients with pacemakers and other similar cardiac devices. In this review, we address the known and theoretical complications of NCS and needle electrode examination, and the possible methods to avoid such hazards. Muscle Nerve 27: 517,526, 2003 [source] Modelling covariance structure in ascending dose studies of isolated tissues and organsPHARMACEUTICAL STATISTICS: THE JOURNAL OF APPLIED STATISTICS IN THE PHARMACEUTICAL INDUSTRY, Issue 2 2003Richard John Brammer This paper describes the analysis of two pharmacology assays: the guinea pig papillary muscle assay (an example of an isolated tissue assay) and an assay looking at pressure changes in isolated rat lungs. Both assays use an ascending dose design to minimize carryover effects. This is often necessary in these studies, due to the limited life span of the tissues. Various mixed models, with different covariance structures, are fitted to find the most appropriate model. These are then compared to two other possible methods of analysis: paired t-tests and two-way analysis of variance. For both assays, the mixed model was found to be the best approach. These examples illustrate the importance of modelling covariance structure correctly in any ascending dose study, whether in isolated organs/tissues, in animals or phase I volunteers. Copyright © 2003 John Wiley & Sons, Ltd. [source] New Method for Predicting the Lumbar Lordosis Angle in Skeletal MaterialTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 12 2007Ella Been Abstract Reconstructing the lordotic curvature of the lumbar spine in humans is essential for understanding their posture and locomotion. To date there is still no reliable method for predicting the lordotic curvature of disarticulated spines (in the absence of intervertebral disks). This article examines two possible methods for predicting the lordotic curvature of the lumbar spine. The first,the traditional method,is based on the degree of wedging of the vertebral bodies, and the second,the suggested new method,is based on a lateral view of the orientation of the inferior articular processes. We propose a linear regression model for predicting the lordotic curvature of the lumbar spine (lordosis angle) in disarticulated human spines. This model, derived directly from our new method, is a more reliable predictor of the lumbar lordosis angle in disarticulated spines. Anat Rec, 2007. © 2007 Wiley-Liss, Inc. [source] A variational method for orographic filtering in NWP and climate modelsTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 619 2006I. C. Rutt Abstract Numerical models of the atmosphere are known to experience problems with near-grid-scale orographic forcing, particularly the formation of spurious grid-point storms. These problems can seriously undermine the accuracy and stability of model integrations, so possible methods for reducing them are of interest. Previous studies indicate that filtering the orographic field is effective in addressing these issues, and they motivate this work. Two potential disadvantages of orographic filtering are the loss of height from important barrier ridges and the adjustment of sea points to non-zero height. To counter these effects, a new variational filtering method is developed, which emulates a class of linear filters but allows the imposition of other conditions on the filtered orography. The properties of the method are explored analytically and confirmed in practice. A representative range of filtered/constrained orographies are then evaluated in a global, nonlinear shallow-water model, under a variety of flow regimes. The results indicate that the benefits of orographic filtering increase as the flow becomes more nonlinear and more balanced; since atmospheric flows are generally more nonlinear and more balanced than the model used here, this evidence is taken to support the use of orographic filtering in an NWP context. The benefits of extra filtering constraints are weakly supported, but they need further evaluation. © Royal Meteorological Society, 2006. The contribution of A. Staniforth is Crown copyright. [source] Use of a retrograde femoral nail in a patient with McCune,Albright syndromeANZ JOURNAL OF SURGERY, Issue 12 2003John D. Garvan McCune,Albright Syndrome is a rare condition characterized by endocrine abnormalities, precocious puberty, pigmented skin lesions and polyostotic fibrous dysplasia with consequent fractures and limb deformity. Patients with this syndrome might have had multiple operations on a limb and might also have extensive internal fixation in-situ. We review the case of a 41-year-old woman with McCune,Albright syndrome, who presented with a pathological fracture of her left femur below a long plate and screws. Our management of this challenging problem included the use of a retrograde femoral nail, which, because of the need to retain pre-existing internal fixation, had to be locked proximally through a hole in a femoral plate. This technique, combined with reaming, and thus bone grafting of the fracture, and also perioperative infusions of pamidronate, allowed an early recovery and return to premorbid function for the patient. In the present study we detail our technique and discuss its advantages over other possible methods of treatment. [source] The colonization of Scottish islands by the common shrew, Sorex araneus (Eulipotyphla: Soricidae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2008THOMAS A. WHITE In this paper we apply molecular methods to study the colonization of islands off the west coast of Scotland by the common shrew (Sorex araneus L.), and current gene flow. We collected 497 individuals from 13 islands of the Inner Hebrides and Clyde Island groups and six mainland regions. Individuals were genotyped at eight microsatellite loci, and the mitochondrial cytochrome b sequence (1140 base pairs) was obtained for five individuals from each island/mainland region. Based on these molecular data, island colonization apparently proceeded directly from the mainland, except for Islay, for which Jura was the most likely source population. Raasay may also have been colonized by island hopping. Most island populations are genetically very distinct from the mainland populations, suggesting long periods of isolation. Two exceptions to this are the islands of Skye and Seil, which are geographically and genetically close to the mainland, suggesting in each case that there has been long-term gene flow between these islands and the mainland. We consider possible methods of island colonization, including human-mediated movement, swimming, and land and ice bridges. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 797,808. [source] Complex dynamic behavior during transition in a solid combustion model,COMPLEXITY, Issue 6 2009Jun Yu Through examples in a free-boundary model of solid combustion, this study concerns nonlinear transition behavior of small disturbances of front propagation and temperature as they evolve in time. This includes complex dynamics of period doubling, and quadrupling, and it eventually leads to chaotic oscillations. Within this complex dynamic domain we also observe a period six-folding. Both asymptotic and numerical solutions are studied. We show that for special parameters our asymptotic method with some dominant modes captures the formation of coherent structures. Finally,we discuss possible methods to improve our prediction of the solutions in the chaotic case. © 2009 Wiley Periodicals, Inc. Complexity, 2009 [source] | |||||||||||||||||||